Per the recommendation of a forum member, I called Benelli customer support and got a gunsmith on the line. This was my first time trying Benelli's support and I was pleasantly surprised. The gunsmith said that they've had this issue come up before and said that applying Loctite 271 to the 1st 3 threads of the recoil tube stock end, then screwing in the stock with stock bolt still connected to the recoil tube spring cap, then letting the loctite set for 24 hours. I should be able to unscrew the stock bolt from the recoil tube spring cap. Once this is done, I will need to use a heat gun to loosen the recoil tube spring cap accordingly. Anyway, this is very logical and apparently works. Hope this helps anyone else who encounters this rare problem.